U.S. patent application number 10/365221 was filed with the patent office on 2003-09-11 for image forming apparatus.
Invention is credited to Funase, Masasuke, Inoshita, Masanori, Ishikawa, Masazumi, Nagaosa, Kazuo, Nakamoto, Masaki, Nishikawa, Hidetoshi, Shima, Kazunobu.
Application Number | 20030169322 10/365221 |
Document ID | / |
Family ID | 27625271 |
Filed Date | 2003-09-11 |
United States Patent
Application |
20030169322 |
Kind Code |
A1 |
Shima, Kazunobu ; et
al. |
September 11, 2003 |
Image forming apparatus
Abstract
An image forming apparatus fixes, by heating, an image formed on
a sheet-like recording medium thereto with sublimating ink. The
apparatus includes a heating fixing unit for receiving and heating
the recording medium and then discharging the heat-fixed recording
medium, the heating fixing unit including a heating space for
heating the recording medium and a transporting mechanism for
transporting the medium in the heating space. The apparatus further
includes a smoothing-out mechanism for discharging the recording
medium from the heating space while smoothing out or flattening the
recording medium.
Inventors: |
Shima, Kazunobu;
(Wakayama-shi, JP) ; Nishikawa, Hidetoshi;
(Wakayama-shi, JP) ; Ishikawa, Masazumi;
(Wakayama-shi, JP) ; Nagaosa, Kazuo;
(Wakayama-shi, JP) ; Nakamoto, Masaki;
(Wakayama-shi, JP) ; Inoshita, Masanori;
(Wakayama-shi, JP) ; Funase, Masasuke;
(Wakayama-shi, JP) |
Correspondence
Address: |
FULBRIGHT & JAWORSKI, LLP
666 FIFTH AVE
NEW YORK
NY
10103-3198
US
|
Family ID: |
27625271 |
Appl. No.: |
10/365221 |
Filed: |
February 12, 2003 |
Current U.S.
Class: |
347/102 ;
399/320 |
Current CPC
Class: |
B41J 11/0005 20130101;
B41J 11/0024 20210101; B41J 15/005 20130101; B41J 11/002 20130101;
B41J 11/00222 20210101 |
Class at
Publication: |
347/102 ;
399/320 |
International
Class: |
B41J 002/01 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 14, 2002 |
JP |
PAT. 2002-36980 |
May 14, 2002 |
JP |
PAT. 2002-138749 |
Dec 4, 2002 |
JP |
PAT. 2002-352597 |
Claims
1. An image forming apparatus for fixing, by heating, an image
formed on a sheet-like recording medium thereto with sublimating
ink, the apparatus comprising: a heating fixing unit for receiving
and heating the recording medium and then discharging the
heat-fixed recording medium, the heating fixing unit including a
heating space for heating the recording medium and a transporting
mechanism for transporting the medium in the heating space; and a
smoothing-out mechanism for discharging the recording medium from
the heating space while smoothing out or flattening the recording
medium.
2. The apparatus according to claim 1, wherein the smoothing-out
mechanism includes a curved transporting section for forcibly
bending the recording medium discharged or being discharged from
the heating space into a direction for bending the medium as viewed
from its lateral side.
3. The apparatus according to claim 2, wherein the curved
transporting section includes an angular member extending straight
along the width direction of the recording medium, a guide
mechanism for forcibly bending the recording medium by pressing the
recording medium against the angular member, and a heating
mechanism for heating the angular member.
4. The apparatus according to claim 3, wherein the angular member
is disposed downwardly of the recording medium to be discharged and
the guide mechanism includes a guide face which is inclined
downward relative to a posture of a leading end of the discharged
recording medium.
5. The apparatus according to claim 1, wherein the apparatus
further comprises a stocker for receiving the recording medium
discharged from the smoothing-out mechanism with a posture in which
the leading end of the medium is inclined downward.
6. The apparatus according to claim 1, wherein the smoothing-out
mechanism includes a press roller mechanism for pressing the
recording medium discharged or being discharged from the heating
space against a flat face.
7. The apparatus according to claim 6, wherein the press roller
mechanism includes a stationary roller supported to be rotatable
about a fixed horizontal shaft and a movable roller supported to be
movable closer to and away from the peripheral face of the
stationary roller, the movable roller being urged in the direction
closer to the peripheral face.
8. The apparatus according to claim 1, wherein the apparatus
further comprise a slow cooling mechanism disposed downstream of
the smoothing-out mechanism in the transporting direction of the
recording medium and adapted for slowly cooling the discharged
recording medium to the normal temperature, and wherein the slow
cooling mechanism includes a guide member having a slide guiding
face along which the recording medium is slid and a heater for
controlling the temperature of the slide guide face to have a
temperature gradient that the temperature of the slide guide face
is lowered gradually along the transporting direction of the
recording medium.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an image forming apparatus
for fixing, by heating, an image formed on a sheet-like recording
medium thereto with sublimating ink.
[0003] 2. Description of the Related Art
[0004] An exemplary conventional technique relating to the above
field of art is disclosed in Japanese patent application "Kokai"
No: Hei. 10-297197. According to this, a metal substrate includes a
coloring ground layer acting also as a rust-preventive layer, a
transparent resin layer as an optical transparent resin layer
formed over the coloring ground layer, the resin layer (made of
e.g. porous alumina) being made of acrylic resin, polyester resin,
urethane resin etc., and an inkjet receiving layer formed over the
resin layer and made of e.g. porous alumina. After application of a
sublimating ink or pigment on the inkjet receiving layer by an
inkjet printing, the sublimating pigment is heated in a heating
furnace or by a hot press, whereby the sublimating pigment in the
inkjet receiving layer is sublimed into the transparent resin
layer. Then, the inkjet receiving layer is removed to obtain an
ornamental metal body having a colored pattern fixedly formed
within the transparent resin layer (see, for example, paragraphs
Nos. 0010-0013 and FIG. 4). This image forming art can be applied
to a recording medium using, as a substrate thereof, metal material
which is hardly deformed by heat. However, if this art is applied
to a recording medium using, as a substrate thereof, e.g. resin
material which is deformed significantly by heat, occurrence of
thermal deformation in the substrate during the heating process,
especially, "wrinkles" cannot be avoided.
[0005] Further, Japanese patent application "Kokai" No: Hei.
10-16188 discloses an image forming apparatus. According to this,
first, a primary image is formed on a thermal transfer sheet by
e.g. an inkjet printer. Then, this thermal transfer sheet having
the image formed thereon is laid over a recording sheet and these
sheets are pressed and heated together by means of heat press
rollers whose temperature is controlled, whereby the image (ink)
formed on the thermal transfer sheet will be sublimed by the heat
and transferred onto an ink fixing layer of the recording sheet
(see, for example, paragraphs Nos. 0008-0012 and FIG. 1). In the
case of this image forming technique, the surface temperature
control of the heat fixing roller is strictly effected. However,
since the contact between the heat press rollers and the recording
sheet is substantially line contact, the surface of the recording
sheet at the normal temperature (room temperature) is heated and
pressed momentarily and then left to cool at the normal temperature
again. Therefore, if material such as resin sensitive to heat is
employed as the substrate of the recording sheet, wrinkles
developed during the heating process will remain after the
cooling.
[0006] According to further art disclosed by Japanese patent
application "Kokai" No: 2001-105638, sublimating ink is transferred
from an ink ribbon onto a surface of a recording sheet. In order to
heat and fix the ink on the sheet, the sheet is charged into a
heater box, in which the sheet is advanced and heated between a
press roller and a heat roller opposed to each other with a small
gap therebetween or between a heat roll and a conveyer belt
disposed along a portion of the peripheral face of the heat roll,
and then the sheet is discharged by a transport roller from the
heater box immediately (see, for example, paragraph Nos. 0039-0058
and FIG. 1). With this image forming technique, the recording sheet
heated by the heating roller is immediately discharged from the
heater box into the normal temperature. Therefore, if material such
as resin sensitive to heat is employed as the substrate of the
recording sheet, wrinkles developed during the heating process will
remain after the cooling.
[0007] Further, though differing in the properties in the recording
medium from the present invention, in the field of textile
printing, according to an exemplary technique disclosed by Japanese
patent application "Kokai" No: Hei. 08-311782, in order to obtain a
print of a graphic image of as clear definition as possible,
printing is effected by means of the inkjet printing method on a
textile whose wrinkles were smoothed out by smoothing out rolls.
After printing, in order to reinforce the fixing of the dye and
also to improve its color development, the textile is charged into
a heater device to be heated therein. Then, the textile is
discharged from the device immediately to be cooled at the normal
temperature (see paragraphs Nos. 0041-0043, 0061-0070 and FIG. 2).
This art, however, does not provide any means for removing
"wrinkles" after completion of the heating process. Therefore, if
this art is employed for a recording material of not textile but
some heat-sensitive material such as resin, the wrinkles developed
during the heating process will remain.
SUMMARY OF THE INVENTION
[0008] In view of the above, a primary object of the present
invention is to provide an image forming apparatus usable for a
recording material using a heat-sensitive material such as resin as
the substrate thereof as the apparatus has a function for
eliminating deformation developed in a recording medium during
heating thereof by a heating fixing unit before cooling of the
medium.
[0009] For accomplishing the above-noted object, according to the
present invention, an image forming apparatus for fixing, by
heating, an image formed on a sheet-like recording medium thereto
with sublimating ink, the apparatus comprising:
[0010] a heating fixing unit for receiving and heating the
recording medium and then discharging the heat-fixed recording
medium, the heating fixing unit including a heating space for
heating the recording medium and a transporting mechanism for
transporting the medium in the heating space; and
[0011] a smoothing-out mechanism for discharging the recording
medium from the heating space while smoothing out or flattening the
recording medium.
[0012] With the above construction, according to the image forming
apparatus of the invention, the recording medium printed with image
with the sublimating ink is introduced into the heating space by
the transporting mechanism, where the medium is exposed to a
required heating process for stably fixing the image thereon. And,
the resultant recording medium is automatically discharged from the
heating space. In the course of this, when the recording medium is
being discharged from the heating space, this medium retaining the
heat received in the heating space, thus having sufficient
plasticity is subjected to the function of the smoothing-out
mechanism. Therefore, even if deformation has occurred during the
heating for ink fixation or due to application of an external force
during its transport, this deformed recording medium may be
effectively smoothed out into the appropriate flat shape.
[0013] Preferably, the smoothing-out mechanism includes a curved
transporting section for forcibly bending the recording medium
discharged or being discharged from the heating space into a
direction for bending the medium as viewed from its lateral
side.
[0014] Namely, in this type of recording medium, there tend to
develop wrinkles in the form of wave-like undulations in the cross
section of the medium. Therefore, with the above-proposed
construction, the recording medium is forcibly bent in the
direction traversing such wave-like undulations, such that such
type of wrinkles may be effectively eliminated or occurrence of
such type of wrinkles may be avoided in advance.
[0015] Preferably, the curved transporting section is arranged in
such a manner as to orient the image-formed face of the recording
medium to the outer side. With this, when the recording medium is
caused to pass the curved transporting section, a tension will
occur on the outer face of the recording medium on which the image
is formed and this tension serves to smooth out fine wrinkles on
the surface of the medium.
[0016] Still preferably, the curved transporting section includes
an angular member extending straight along the width direction of
the recording medium, a guide mechanism for forcibly bending the
recording medium by pressing the recording medium against the
angular member, and a heating mechanism for heating the angular
member.
[0017] With this construction, the width-wise entire area of the
recording medium will be pressed at one time against a projecting
portion of the angular member extending straight, so that the
medium may be subjected to a uniform smoothing-out effect
particularly in the width direction thereof. Further, this angular
member is heated to a high temperature by the heating mechanism,
the recording medium discharged from the heating space and having a
gradually reducing temperature can be heated again for recover its
thermal plasticity and processed under this condition.
Consequently, the recording medium may be bent smoothly, thus
realizing very effective smoothing out of the medium.
[0018] The angular member can be considered as a group of
infinitely small and an infinite number of smoothing-out elements
arranged straight along the main scanning direction. And, the
recording medium being moved in the sub scanning direction by the
transporting mechanism can be considered as being discharged while
being uniformly smoothed out in the width direction thereof along
and on these smoothing-out elements.
[0019] Preferably, the angular member is disposed downwardly of the
recording medium to be discharged and the guide mechanism includes
a guide face which is inclined downward relative to a posture of
the leading end of the discharged recording medium.
[0020] With this construction, the leading end of the recording
medium discharged from the heating space of the heating fixing unit
will be pressed against the inclined guide face to be oriented
downward. Thus, the bending of the recording medium in the side
view thereof may take place smoothly. Further, this bending will
occur such that the transportation-wise downstream portion of the
medium is bent downward, which bending direction agrees with the
bending direction under the gravity, i.e. under the effect of the
dead weight of the recording medium per se. Therefore, the
recording medium bent by the curved transporting section can be
effectively pressed against the corner of the angular portion with
the help of the dead weight of the recording medium i.e. the
gravity.
[0021] Preferably, downwardly of the guide face, there is provided
a partitioning wall for forming an open space around the recording
medium. With this, by maintaining the air temperature of this pace
at a relatively high value, discharge of heat from the angular
member or the exit of the heating space may be effectively
restricted. At the same time, this can restrict rapid discharge of
heat from the recording medium discharged from the heating space.
Consequently, as the recording medium is guided with an appropriate
posture thereof while the angular member of the inside of the
heating space is maintained at the relatively high temperature, the
smoothing-out operation on the recording medium can proceed
effectively and appropriately.
[0022] Still preferably, the apparatus further comprises a stocker
for receiving the recording medium discharged from the
smoothing-out mechanism with a posture in which the leading end of
the medium is inclined downward.
[0023] With this construction, even when the recording medium past
the smoothing-out section is discharged in the form of being
dropped or when an elongated medium is discharged continuously, the
recording medium may be received by the stocker with the lower end
of the medium being caused to slide on the inclined face of the
stocker disposed below. Therefore, by guiding the recording medium
along the inclination direction of the stocker, the medium can be
collected compactly and smoothly.
[0024] Alternatively, the smoothing-out mechanism includes a press
roller mechanism for pressing the recording medium discharged or
being discharged from the heating space against a flat face.
[0025] With this, it become possible to apply the pressing force to
the recording medium in a reliable manner, regardless of difference
in the thickness of the recording medium. Adjustment of the
pressing force is possible by e.g. attaching a weight to the
roller. Needless to say, it will be also possible to apply a
predetermined urging force to the roller by means of e.g. a spring.
However, the construction utilizing a dead weight alone will be
simpler and less costly. With this construction, any deformation
such as wrinkles developed in the surface of the recording medium
during the heating process by the heating fixing unit may be
"ironed out" by the effect of the press roller on the medium still
having high temperature and associated plasticity at the last stage
of the heating process. Hence, the deformation such as wrinkles may
be eliminated before the medium is cooled. Therefore, such wrinkles
will not remain in the final printed product after the cooling
process.
[0026] Preferably, the press roller mechanism includes a stationary
roller supported to be rotatable about a fixed horizontal shaft and
a movable roller supported to be movable closer to and away from
the peripheral face of the stationary roller, the movable roller
being urged in the direction closer to the peripheral face.
[0027] With this construction, as the movable roller is movable
closer to and away from the peripheral face of the stationary
roller, the press roller mechanism can receive recording media of
various thicknesses. Further, the press roller mechanism can
receive also a recording medium having very large wrinkles in the
thickness direction thereof. Further, as the movable roller is
urged in the approaching direction, this roller can positively
contribute to the smoothing of the deformation such as
wrinkles.
[0028] Incidentally, the deformation such as wrinkles developed in
the surface of the recording medium during the heating process at
the heating fixing unit may be dissolved by e.g. the ironing effect
of the press roller mechanism. However, if the recording medium is
suddenly discharged from the heating fixing unit to the outside,
resultant rapid cooling experienced by the recording medium from
the temperature inside the heating space to the room temperature
can lead to new occurrence of deformation such as wrinkles in the
medium.
[0029] Then, the apparatus may further comprise a slow cooling
mechanism disposed downstream of the smoothing-out mechanism in the
transporting direction of the recording medium and adapted for
slowly cooling the discharged recording medium to the normal
temperature, and the slow cooling mechanism includes a guide member
having a slide guiding face along which the recording medium is
slid and a heater for controlling the temperature of the slide
guide face to have a temperature gradient that the temperature of
the slide guide face is lowered gradually along the transporting
direction of the recording medium.
[0030] With the above construction, the recording medium which was
heated at the heating fixing unit for heat fixation of the printed
image is slowly returned from the ink fixing temperature
(generally, 150.degree. C. or more) to the normal temperature (room
temperature) by the slow cooling mechanism. As a result, occurrence
of deformation such as wrinkles due to rapid cooling from the
temperature inside the heating fixing unit (ink fixing temperature)
to the normal temperature (room temperature) may be effectively
restricted. Accordingly, there has been realized an image forming
apparatus which can not only eliminate the wrinkles developed in
the heating process, but also avoid further wrinkles which could
occur during the cooling process.
[0031] Further and other features and advantages of the invention
will become apparent upon reading the following detailed
description of preferred embodiments thereof with reference to the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] FIG. 1 is a section view showing an example of recording
medium to be processed by the present invention,
[0033] FIG. 2 is an appearance view of an image forming apparatus
according to one preferred embodiment of the invention,
[0034] FIG. 3 is a schematic section showing a construction of a
printing station of the image forming apparatus,
[0035] FIG. 4 is a schematic section showing a construction of a
printing unit included in the printing station,
[0036] FIG. 5 is a schematic section showing constructions of a
heating fixing unit and a slow cooling subunit,
[0037] FIG. 6 is a perspective view showing constructions of a
press roller mechanism and the slow cooling unit,
[0038] FIG. 7 is an enlarged schematic section showing a
construction of a smoothing-out mechanism,
[0039] FIG. 8 is a perspective view showing a layout of an electric
wire provided in a slow cooling guide member,
[0040] FIG. 9 is a schematic view showing a further layout of the
electric wire provided in the slow cooling guide member,
[0041] FIG. 10 is a schematic view showing a layout of the electric
wire provided in the slow cooling guide member according to a
further embodiment,
[0042] FIG. 11 is a functional block diagram illustrating various
functions of a controller,
[0043] FIG. 12 is a section view showing a printing station
according to a further embodiment, and
[0044] FIG. 13 is an enlarged section view showing a smoothing-out
mechanism according to a still further embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0045] A preferred embodiment of an image forming apparatus
relating to the present invention will be described with reference
to the accompanying drawings.
[0046] (Recording Medium)
[0047] First, an example of a recording medium 1 to be processed by
the invention will be described with reference to FIG. 1. This
recording medium 1 includes a substrate 10 made of a film sheet of
e.g. PET (polyethylene terephthalate), a fixing layer 11 formed of
e.g. urethane resin and placed over the surface of the substrate 10
for fixing therein ink, that is, ink pigment, and a surface layer
12 placed on the surface of the layer 11 and acting as a receiving
layer for receiving the ink. In case the surface of the substrate
10 has a property allowing direct fixation of the ink pigment
thereon, the fixing layer 11 may be omitted. In use, ink droplets
are applied by e.g. an inkjet printer to the surface layer 12 of
this recording medium 1 to form thereon a printed image
constituted, after which, when heated to an appropriate
temperature, the ink droplets (un-sublimated print dots) applied on
the surface layer 12 begin to sublime and permeate the surface
layer 12 to reach the underlying fixing layer 11, so that the ink
pigment, now as sublimated print dots, is fixed within the fixing
layer 11. Accordingly, by removing or "peeling off" the surface
layer 12, there will be obtained, as a final printed product 100,
an image recorded sheet having high gloss and high image definition
bearing the printed image formed of the sublimated print dots in
its fixing layer 11. Incidentally, as this recording medium
requires, at the last stage, removal of the surface layer 12 from
the fixing layer 11 or the substrate 10, it will be advantageous to
provide a releasing agent therebetween.
[0048] (Image Forming System)
[0049] Next, an exemplary image forming system for producing the
final printed product 100 with using the above-described recording
medium 1 will be described with reference to FIG. 2 and FIG. 3. As
shown, this image forming system consists mainly of a printing
station PS and an operator's station OS.
[0050] (Printing Station PS)
[0051] The printing station PS includes an inkjet type printing
unit PU, a loop-forming unit RU for temporarily holding the
recording medium 1 bearing a printed image formed of un-sublimated
print dots by the printing unit PU, and a heating fixing unit HU
for applying thermal energy to the recording medium 1 sent from the
loop-forming unit RU to produce a printed image formed of
sublimated print dots, and a slow cooling unit CU for slowing
cooling the recording medium 1 discharged from the heating fixing
unit HU to a normal temperature (room temperature). Adjacent the
exit of the heating fixing unit HU, there is provided a
smoothing-out mechanism D for discharging the recording medium 1
from the heating space of the heating fixing unit while smoothing
out or flattening this medium 1. This smoothing-out mechanism D
includes a press roller mechanism 58 and a curved transporting
section 59.
[0052] Incidentally, the loop-forming unit RU provided between the
printing unit PU and the heating fixing unit HU serves to absorb a
speed difference existing between a relatively low transport speed
of the recording medium 1 provided by the heating fixing unit HU
and a relatively high average transport speed of the medium 1
provided by the printing unit PU. The printing unit PU,
loop-forming unit RU and the heating fixing unit HU are provided as
separate units detachably connectable to each other. The slow
cooling subunit CU is attached to the heating fixing unit HU.
[0053] (Printing Unit PU)
[0054] As can be seen from FIG. 4, within the printing unit PU, a
sheet transport mechanism 6 transports the recording medium 1 while
unwinding this recording medium 1 from an unillustrated roll-sheet
cartridge in which the medium 1 is stored in the form of a roll, in
such a manner that the surface layer 12, the printing surface, of
the medium may be brought adjacent an ink discharging outlet of an
inkjet type print head 2. The print head 2 is mounted to be movable
back and forth by a head feeding mechanism 3 along a direction
traversing the transporting direction of the recording medium 1
(that is, along a main scanning direction). As the recording medium
1 is transported along a sub-scanning direction with each stroke of
movement of the print head 2 in the main scanning direction with
discharging ink through its ink discharging outlet against the
surface layer 12 of the recording medium 1, printed images will be
formed in succession.
[0055] The print head 2 includes a plurality of discharging outlet
modules capable of respectively discharging inks of different
principal colors depending on the characteristics of the color
printed image to be formed. For instance, if a color printed image
of photographic quality is needed, in addition to inks of primary
colors of cyan, magenta, yellow, black etc, further inks of tint
colors of same kind will be generally used. The print head 2 may be
a standard print head used in a conventional inkjet printer. After
a printed image is formed on its surface layer 12 with the ink
droplets 2a discharged from the print head 2, the recording medium
1 exits the printing unit PU to enter the loop-forming unit RU.
[0056] The recording medium 1 is provided in the form of an
elongate sheet from its manufacturer. Hence, it is necessary to cut
it to a size of a printed image formed thereof. To this end, a
sheet cutter means 5 is provided. In this embodiment, the sheet
cutter means 5 includes a cutter blade body 51 switchable between a
position where the body projects toward the recording medium 1
relative to the print head 2 and a further position where the body
is retracted away from the recording medium 1, and a switchover
motor 52 for switching over the cutter blade body 51 between the
two positions through e.g. a cam-feed or screw-feed mechanism (not
shown).
[0057] (Loop-Forming Unit RU)
[0058] Though shown only schematically in FIG. 3 the loop-forming
unit RU includes a turn roller 32 having three driven rollers 31 at
the center thereof, a first loop-forming mechanism 30A disposed
transportation-wise upstream of the turn roller 32, a second
loop-forming mechanism 30B disposed transportation-wise downstream
of the turn roller 32, and a case 33 for receiving the recording
medium 1 at a position downwardly of these components.
[0059] The turn roller 32 is driven by an unillustrated motor; and
as its three driven rollers 31 are pressed against the outer
periphery of this turn roller 32, the turn roller 32 winds the
recoding medium 1 about it, so that this roller 32 provides a
function for eliminating or adjusting any curling tendency present
in the recording medium 1 as furnished from its manufacturer. The
first loop-forming mechanism 30A includes an introduction guide 34
for downwardly guiding the recording medium 1 discharged from an
exit of the printing unit PU, a first stationary guide 35 for
further downwardly guiding the recording medium 1 which has been
guided downwardly by the introduction guide 34 and a first movable
guide 36 disposed in opposition to the first stationary guide 35.
The first movable guide 36 is pivotable by means of an
unillustrated motor about a pivot axis disposed at the top end of
the guide, so that the guide 36 can selectively assume a closed
posture denoted with a solid line or a opened posture denoted with
a virtual line.
[0060] The second loop-forming mechanism 30B includes a second
stationary guide 37 for guiding the recording medium 1, which has
been transported from the first loop-forming mechanism 30A via the
turn roller 32, to the heating fixing unit HU, a second movable
guide 38 disposed in opposition to the second stationary guide 37,
and a clamping type feed roller 39 for feeding the recording medium
1 to the heating fixing unit HU. The second movable guide 38 is
pivotable by means of an unillustrated motor about a pivot axis
disposed at the top end of the guide, so that the guide 38 can
selectively assume a closed posture denoted with a solid line or a
opened posture denoted with a virtual line.
[0061] In this loop-forming unit RU, at respective positions along
the transport passage of the recording medium 1, sensors (not
shown) are provided for detecting presence/absence of the recording
medium 1 and a control operation described below is effected based
on detection signals from these sensors. Namely, when the recording
medium 1 is discharged from the printing unit PU, the first movable
guide 36 is set to its closed posture and also the turn roller 32
is rotated at a low speed, thereby to guide the leading end of this
recording medium 1 from the introduction guide 34 to the turn
roller 32. Upon confirmation of clamped retention of the leading
end of the recording medium 1 between the turn roller 32 and the
driven rollers 32, the first movable guide 36 is switched over to
its opened posture, whereby the recording medium 1 is stored under
a suspended condition within the first loop-forming mechanism
30A.
[0062] Next, upon detection of the tailing end of the recording
medium 1 transported from the printing unit PU, the second movable
guide 38 is set at its closed posture and under this condition, the
control initiates driving of the turn roller 32 and the feed roller
39, thereby to transport the leading end of the recording medium 1
to the feed roller 39 of the second loop-forming mechanism 30B, so
that the feed roller 39 clamps the leading end of the recording
medium 1 and proceeds to send the medium into the heating fixing
unit HU at a speed substantially equal to the transport speed of
the recording medium 1 by the heating fixing unit HU and at the
same time, after switching over the second movable guide 38 to its
opened posture, the turn roller 32 is driven to rotate at a high
speed, whereby the recording medium 1 retained within the first
loop-forming mechanism 30A is stored under a suspended condition
within the second loop-forming mechanism 30B. In this way, upon
sending of the recording medium 1 from the first loop-forming
mechanism 30A into the second loop-forming mechanism 30B, the
control operation is resumed for introducing the recording medium 1
from the printing unit PU into the first loop-forming mechanism 30A
in the manner described above.
[0063] (Heating Fixing Unit HU)
[0064] As shown in FIG. 3 and FIG. 5, the heating fixing unit HU
includes, within a main casing 50 thereof supported by a support
leg 53, a heating case 51 made of insulating material for heating
the recording medium 1, and a blower case 52 also made of
insulating material and disposed above the heating case 51 for
supplying hot air to this heating case 51. Inside the heating case
51, adjacent an entrance thereof, there is formed a preliminary
heating space PR and in succession to this preliminary heating
space PR, a heating space R is formed. In the preliminary heating
space PR and the heating space R, there is disposed a heating
transport mechanism 54 for transporting the recording medium 1, the
heating transport mechanism 54 constituting a part of the sheet
transport mechanism 6.
[0065] This heating transport mechanism 54 includes guide members
54c provided in the preliminary heating space PR (one) and in the
heating space R (two) for coming into contact with the lower face
of the recording medium 1 for transmitting heat to the medium 1, a
pair of clamping type introducing rollers 54a disposed adjacent the
entrance of the heating fixing unit HU for introducing the
recording medium 1 (inside the preliminary heating space PR), a
pair of transport roller mechanism 54b disposed between the
respective guide members 54c for transferring the recording medium
1 to the next adjacent guide member 54c, and a press roller
mechanism 58 disposed adjacent the exit of the heating fixing unit
HU for discharging the recording medium 1 past the last guide
member 54c from the heating fixing unit HU.
[0066] The transport roller mechanism 54b includes one lower roller
for supporting the back face of the recording medium 1 and two
upper rollers disposed parallel with each other for pressing the
recording medium 1 against the lower roller, with these three
rollers being rotatable about stationary horizontal shafts. Only
the lower roller is driven while the upper rollers are free
rollers. In order not to give a curling tendency to the recording
medium 1, the two upper rollers are arranged at such positions as
to form a gap exceeding the thickness of the recording medium 1
between the upper rollers and the lower roller and also to allow
the recording medium 1 to be pressed lightly, by its own rigidity,
against both the upper rollers and the lower roller. Incidentally,
upwardly of the respective guide members 54c too, there are
provided a plurality of upper face contact rollers 54d as drive
rollers for coming into light contact with the upper face of the
recording medium 1 for applying a transporting force thereto.
[0067] The press roller mechanism 58 constitutes a portion of a
smoothing-out mechanism D for discharging the recording medium 1
from the heating space of the heating, fixing unit HU while
smoothing out, i.e. shaping the medium 1 flat. Further, immediately
transportation-wise downstream of this press roller mechanism 58,
there is provided a curved transporting section 59, which also
constitutes a portion of the smoothing-out mechanism D for
flattening the recording medium 1 while it is being discharged from
the heating space of the heating fixing unit HU.
[0068] On the lower face of the guide member 54c disposed
downwardly of the upper face contact rollers 54d, there are
provided a sheet heater 55 for heating this guide member 54c and a
fixing temperature sensor 41 disposed at the center of this sheet
heater 55 for measuring the temperature of the guide member
54c.
[0069] Inside the blower case 52, there are provided an electric
heater 56 in the form of a plurality of rods and a crossflow fan 57
for driving fan blades about an axis extending parallel with the
width of the recording medium 1 for feeding hot air. This blower
case 52 defines, in its bottom face, an outlet E located
immediately below the crossflow fan 57 for discharging hot air and
an inlet F located upstream on the transporting passage for the
recording medium 1 by the heating transporting mechanism 54.
Adjacent the aperture of the outlet E, there is provided an air
sensor 42 in correspondence with the crossflow fan 57.
[0070] When the recording medium 1 is heated, the electric heater
56 and the crossflow fan 57 are driven, thereby to feed the air
heated within the blower case 52 through the outlet E to a position
transportation-wise downstream of the recording medium 1 inside the
heating case 51 for a feeding width greater than the entire width
of the recording medium 1, so that this hot air is caused to flow
toward the transportation-wise upstream side along the transporting
passage of the recording medium 1. Then, the air is drawn into the
blower case 52 through the inlet F at a position
transportation-wise upstream of the recording medium 1 to be heated
by the electric heater 56. After this, the heated air is supplied
to the crossflow fan 57. In this way, the heated air is
circulated.
[0071] In controlling the heating fixing process, power is supplied
to the respective electric heaters 56 so that the air temperature
sensor 42 may sense temperature of about 180.degree. C., and to the
respective sheet heaters 55 so that the fixing temperature sensor
41 inside the preliminary heating space PR may sense temperature of
about 100.degree. C., the transportation-wise upstream fixing
temperature sensor 41 inside the heating space R may sense
temperature of about 130.degree. C., and the transportation-wise
downstream fixing temperature sensor 41 may sense temperature of
180.degree. C., respectively. These target temperatures will be
varied in accordance with the properties of the recording medium 1
(including its thickness), the properties of the ink, etc.
[0072] (Press Roller Mechanism 58)
[0073] The press roller mechanism 58 is disposed adjacent the exit
of the heating fixing unit HU and, as shown in FIG. 6 and FIG. 7,
the mechanism includes a first roller 58a for coming into contact
with the back surface of the recording medium 1, a second roller
58b disposed transportation-wise upstream of the first roller 58a
and adapted for coming into contact with the front surface of the
recording medium 1, a third roller 58c disposed transportation-wise
downstream of the first roller 58a and adapted for coming into
contact with the front surface of the recording medium 1 and a
bracket 58e for rotatably supporting roller shafts 58d of these
rollers.
[0074] These three rollers are disposed basically at the same
position of the transport roller mechanism 54b and in this case too
only the first roller 58a is a drive roller. Further, roller shafts
58d of the first roller 58a and the second roller 58b are supported
to the bracket 58e immovably and with substantially horizontal
posture. Whereas, the roller shaft 58d of the third roller 58c is
inserted into a vertical guide hole 58f defined in the bracket 58e,
so that the third roller 58c presses, by its dead weight, the
recording medium 1 between this third roller and the peripheral
face of the first roller 58a. Incidentally, opposed ends of the
roller shaft 58d of the third roller 58c are independently
vertically movable within the corresponding guide holes 58f. That
is to say, this third roller 58c can also assume an inclined
posture relative to the horizontal with the range permitted by the
length of the guide hole 58f.
[0075] Each of these rollers of the press roller mechanism 58 has a
length longer than the maximum width of the recording medium 1 and
the roller comprises a metal drum having laminated foamed resin on
its surface. And, the dead weight of the third roller 58c is set so
that when the roller presses the recording medium 1 therebetween
with the first roller 58a, an ironing effect is generated for
smoothing out wrinkles or the like which may have developed in the
recording medium 1 during the heating fixing process. Although the
value of this dead weight will be determined through experiment or
experimentally depending on the plasticity of the recording medium
1 when adjacent the press roller mechanism 58 or the load (depends
on the length and the outer diameter of the roller) per unit area
to be applied to the medium, any adjustment in this weight will be
effected by means of a weight provided as an accessory. Needless to
say, it is also possible to provide, by means of a spring or the
like, the third roller 58c with an urging force toward the
peripheral face of the first roller 58a.
[0076] As may be apparent from FIG. 7, the axis of the third roller
58c is offset to the downstream side from the axis of the first
roller 58a relative to the transporting direction. With this offset
arrangement, the tangent between the third roller 58c and the first
roller 58a is inclined downwardly from the horizontal by a range of
5 degrees to 60 degrees (30 degrees in the case of the example
shown in FIG. 7). As a result, the recording medium 1 will be bent
at this pressing area slightly downward. Namely, the press roller
mechanism 58 constitutes a curved transporting section for forcibly
bending the recording medium 1 discharged or being discharged from
the heating space into a direction where the recording medium 1 is
bent as viewed from its lateral side. Therefore, it may be said
that this press roller mechanism 58 constitutes a "smoothing-out
mechanism D" which provides the two effects, i.e. the ironing
effect by the pressing action from the rollers and the flattening
effect based on bending of the medium into a predetermined
posture.
[0077] Incidentally, all of the rollers constituting the heating
transporting mechanism 54 are driven directly or indirectly via an
unillustrated transmission belt. In this, although the third roller
58c has its roller shaft 58d movable to and away from the recording
medium 1, this third roller 58c may be driven by means of a
transmission mechanism having a tension adjusting pulley or the
like which per se is well-known.
[0078] (Curved Transporting Section 59)
[0079] The curved transporting section 59 is disposed downstream
adjacent the press roller mechanism 58. The section comprises a
guide body 59a having a guide face for guiding the recording medium
1 such that its face bearing an image may be oriented to the
outside. The guide face of the guide body 59a has a mildly arc-like
cross section having a radium of about 40 to 120 mm. Further,
arrangement is made such that an extension line of the recording
medium 1 clamped between the third roller 58c and the first roller
58a of the press roller mechanism 58 is in substantial agreement
with a common tangent of the guide face of the guide body 59a and
the first roller 58a.
[0080] When the recording medium 1 is slid along the face of such
guide body 59a while being pressed against it (by the dead weight
of the recording medium 1 slid down from the slow cooling unit CU
to be described later), there is generated a tension on the front
surface of the medium 1, which force serves to smooth out fine
surface wrinkles therein.
[0081] Incidentally, in the recording medium 1, there tend to
develop such type of wrinkles which appear as wave-like undulations
in the cross section of the medium 1. Therefore, by forcibly
bending the recording medium 1 in which such wrinkles are being
developed in the direction traversing these wave-like undulations,
the wrinkles may be effectively eliminated. For this reason, the
curved transporting section 59 too constitutes a part of the
"smoothing-out mechanism D". If needed, a sheet heater and a
temperature sensor may be provided also in the guide body
constituting the curved transporting section 59 for allowing
feedback temperature control.
[0082] (Slow Cooling Unit CU)
[0083] The slow cooling subunit CU, as shown in FIG. 5 and FIG. 6,
includes a slow cooling guide member 92 acting as a transportation
guide body for the recording medium 1, a slow cooling intermediate
transporting roller pair 94, and a turn guide 95, a discharging
roller pair 96 and these components together constitute a slow
cooling transporting line inclined downward for the recording
medium 1. This slow cooling transporting line is disposed inside a
slow cooling space which is substantially closed by a slow cooling
case 91. The slow cooling guide member 92 extends with a width
exceeding the maximum width of the recording medium 1 so as to form
an inclined guide face for coming into face contact with the
recording medium 1. The inclination of the inclined face is
determined within a range between 20 degrees and 60 degrees
relative to the vertical axis (about 60 degrees in the case of the
exemplary construction shown in FIG. 5). To the rear face or inside
of the slow cooling guide member 92, there is mounted an electric
wire 93 for transmitting heat to this slow cooling guide member
92.
[0084] The layout of the electric wire 93 and the amount of power
to be supplied thereto are set such that the temperature at the
recording medium entrance of the slow cooling guide member 92 may
be substantially equal to the temperature at the exit of the
heating fixing unit HU and also that the temperature at the
recording medium exit of the slow cooling guide member 92 may be
substantially equal to the room temperature and also the
temperature gradient therebetween may form as mild as possible
curve. With this, occurrence of deformation such as wrinkles in
recording medium 1 during its cooling process may be effectively
restricted. Specifically, to this end, as shown in FIG. 8, the
electric wire 93 is arranged in such a manner as to provide a
relatively high disposing density on the transportation-wise
upstream side relative to the slow cooling guide member 92 and a
relatively low disposing density on the transportation-wise
downstream side. In order to obtain a temperature gradient having
as mild as possible curve, as shown in FIG. 9, a meander layout
having continuously variable disposing pitch may be employed also.
In the embodiment modes of FIG. 8 and FIG. 9, the electric wire 93
comprises a single wire. Hence, by varying the power to be supplied
to the electric wire 93, the temperature in the slow cooling guide
member 92 will be raised or lowered correspondingly.
[0085] As a predetermined electric current is supplied to this
electric wire 93, in the slow cooling guide member 92, there is
developed such temperature gradient described above effective for
restricting occurrence of wrinkles, e.g. temperature gradient from
about 180.degree. C. to 20.degree. C. This control of the power to
be supplied to the electric wire 93 is effected with accuracy by
means of the controller 7, using, as feedback, the detection signal
from a slow cooling temperature sensor 43 disposed directly at the
intermediate area of the slow cooling guide member 92 or disposed
upwardly of the guide face. Therefore, the slow cooling unit CU too
constitutes a part of the "smoothing-out mechanism D".
[0086] As an embodiment allowing desired adjustment of the
temperature gradient in the slow cooling guide member 92 in the
transporting direction, for instance, as shown in FIG. 10, the
electric wire 93 may be divided into a first electric wire 93a, a
second electric wire 93b, a third electric wire 93c, a fourth
electric wire 93d, and so on, in the order from the area adjacent
to the recording medium entrance to the area adjacent the recording
medium exit, so as to allow independent control of the power to be
supplied to the respective wires. In this case, at positions
corresponding to these respective electric wires 93a, 93b, 93c, 93d
. . . , a plurality of slow cooling temperature sensors 43a, 43b,
43c, 43d . . . will be provided, so that the respective electric
wires may be feedback controlled whereby a desired temperature
gradient may be developed in the slow cooling guide member 92 as a
whole. This alternative construction will be particularly
advantageous in such case where the fixing temperature greatly
varies depending on the type of the recording medium 1 employed or
the room temperature significantly varies from one season to
another.
[0087] In order to receive the recording medium 1 discharged from
the slow cooling unit CU, as shown in FIGS. 2 and 3, there is
provided a stocker ST. This stocker ST comprises a box-like member
having a width greater than the maximum width of the recording
medium 1 which can be processed. And, its inside has a lining of
sheet interwoven with carbon fibers having conductivity for
eliminating static electrical charge. Further, as the recording
medium 1 discharged from the slow cooling unit CU has a certain
amount of curling tendency, then, by utilizing this curling
tendency, the medium will be wound without a core inside the
stocker ST for storage therein. In the recoding medium 1 wound and
stored within the stocker ST, the ink (pigment) forming its printed
image are already fixed within the fixing layer 11. Then, by
removing the surface layer 12, a finished printed product 100
having a clearly color-developed image may be obtained.
[0088] (Controller 7)
[0089] As shown in FIG. 11, the controller 7 functioning as a
control unit for the image forming apparatus having the
above-described construction includes a first controller 7A
provided in an operator's station OS and a second controller 7B
provided in the printing station PS, with the two controllers 7A,
7B being connected to each other via communication cable for
allowing data exchange therebetween, so that the two controllers
7A, 7B may function just like a single controller.
[0090] (Operator's Station OS)
[0091] As shown in FIG. 2, the operator's station OS includes a
general-purpose computer 80 acting also as the first controller 7A,
a monitor 81, a keyboard 82, a mouse 83, a film scanner 85 for
effecting conversion of a photographic image of a developed
photographic film F into image data, and an image reading unit 84
(in this case, this unit is incorporated within the computer 80)
for reading or obtaining image data from a data storage medium (CD,
CD-R, MO, or any kind of semiconductor memory device such as
Compact-Flash or Smart-Media as well as any communication media
comprising a data communication line). In the case of this image
forming apparatus, the image data obtained by the film scanner 85
or the image reading unit 84 and then transmitted to the first
controller 7A will be subjected to various necessary data
processing operations and then the processed image data will be
transmitted as source print data to the second controller 7B, so
that a printed image will be formed on the recording medium 1 at
the printing station PS and heated and fixed thereon.
[0092] As described above, the controller 7 includes the first
controller 7A and the second controller 7B each having as a major
component thereof a microcomputer system having CPU, ROM, RAM, I/O
interface circuit etc.
[0093] As shown in FIG. 11, to the first controller 7A, via the I/O
interface circuit, there are connected such peripheral devices as
the image reading unit 84, the film scanner 85, etc. To the second
controller 7B, via its I/O interface circuit, there are connected
the peripheral devices incorporated in the printing station PS
including the inkjet print head 2, the head feeding mechanism 3,
the electric heaters 56, the crossflow fan 57, the recording medium
transporting mechanism etc.
[0094] Further, a recording medium type detecting sensor 44 is
provided for detecting an ID code provided on the roll sheet
cartridge or on a shaft member supporting the recording medium 1
around it in the rolled state and this sensor transmits its type
detection signal to the controller 7, so that the controller 7 may
recognize the type of the charged recording material 1 based on
this detection signal. The first controller 7A and the second
controller 7B are capable of data transmission via respective
communication modes thereof. For instance, the image data having
been subjected to the image processing and adjustment processing at
the first controller 7A will be converted into final print data,
which will then be transmitted to the second controller 7B via the
communication module 74a, 74b to be subsequently used for e.g.
application of the sublimating ink to the recording medium 1.
[0095] The various functions provided by the controller 7 are
realized by means of hardware and/or software. Referring here to
only those functional elements having relevance to the present
invention, the following sections are provided as typical examples;
namely, an image data inputting section 71 for effecting
pre-processing on the image data obtained by the image reading unit
84 or the film scanner 85 such as a format conversion or resolution
conversion; an image processing section 72 for effecting image
adjustments on the image data transmitted from the image data
inputting section 71 such as a trimming or color adjustment; a
print data generating section 73 for generating source print data
for subsequent use by the print head 2 from the final image data by
implementing a binarizing method such as an error diffusing method;
a print controlling section 75 for driving the print head 2 in
accordance with the transmitted print data for discharging ink
droplets through the outlet; a transportation controlling section
76 for controlling the intermittent feeding of the recording medium
1 inside the printing unit PU in synchronism with the movement of
the print head 2 in the main scanning direction, the loop transport
of the recording medium 1 inside the loop-forming unit RU as well
as the transport and heating of the recording medium within the
heating fixing unit HU and transport of the medium 1 from the slow
cooling unit CU (by means of the slow cooling intermediate roller
pair 94 and the discharge roller pair 96); a heating controlling
section 77 for controlling the power supply to the electric heaters
56 and the crossflow fan 57 of the heating fixing unit HU; a slow
cooling controlling section 78 for controlling the power supply to
the electric wire 93 as the heater for the slow cooling guide body
92 based on the temperature detected by the slow cooling
temperature sensor 43; and a recording medium type identifying
section 79 for obtaining type data of the charged recording medium
1 based on the ID code thereof read by the recording medium type
detecting sensor 44. Incidentally, the slow cooling controlling
section 78 can effect the control of the power supply to the
electric wire 93, with taking into consideration, also if needed,
such additional information concerning the recording medium type
information obtained by the recording medium type identifying
section 79 and the room temperature.
[0096] (Process of Image Formation)
[0097] Next, there will be described a typical process for
producing a final printed product by using the image forming
apparatus having the above-described construction.
[0098] <1>Printed Image Forming Stage
[0099] First, image data in the JPEG format read from the MO disc
by means of the image reading unit 84 are transmitted as image
source for this image forming apparatus to the image data inputting
section 71. At this image data inputting section 71, the JPEG image
data are mapped into 8-bit RGB color image data and then
transmitted to the image processing section 72. Then, the image
data are processed in accordance with the print size, trimming
setting command, color adjustment command etc. inputted by the
operator by operation of the keyboard 82 or the mouse 83. Upon
completion of the predetermined image processing, the image data
will be transmitted to the print data generating section 73.
Incidentally, since the RGB color data have already been converted
into the CMYK color image data at an appropriate stage after or
before the other image processing, the color data transmitted to
the print data generating section 73 are CMYK color image data. At
this print data generating section 73, the CMYK color image data
are converted into binary CMYK print data, which are then
transmitted to the print controlling section 75. As described
hereinbefore, the print controlling section 75 generates drive
pulse signals for the print head 2 from the transmitted binary CMYK
print data, whereby the drive elements of the print head 2 are
controllably driven to form an image on the recording medium 1 with
ink dots.
[0100] <2>Image Fixing Formation Stage
[0101] After being subjected to a necessary timing adjustment at
the loop-forming unit RU, the recording medium 1 having an image
formed on its surface layer 12 is caused to pass the preliminary
heating space PR and the heating space R which are appropriately
temperature-conditioned, during which the medium is exposed to
thermal energy and with associated heating sublimation, the image
formed on the surface layer 12 is transferred (fixed) to the fixing
layer 11. Then, the recording medium 1 having undergone this
heating fixing process will have its wrinkles developed during the
heating process smoothed out by the press roller mechanism 58
disposed at the exit of the heating fixing unit HU and by the
curved transporting section 59 to be introduced to the slow cooling
unit CU.
[0102] <3>Slow Cooling Stage
[0103] Thereafter, the recording medium 1 introduced in the slow
cooling unit CU will be transported obliquely downward along the
surface of the slow cooling guide member 92 and pinched by the slow
cooling intermediate transport roller pair 94. Then, the medium 1
will be returned to the substantially horizontal posture by means
of the turn guide 95 and the discharge roller pair 96 disposed
obliquely downwardly thereof and discharged to the outside of the
printing station PS. The discharged recording medium 1 will be
stored within the stocker ST. Then, when appropriate, by removing
the surface layer 12 from the medium, there will be obtained a
finished printed product 100 having an image with clear color
development.
[0104] In the foregoing embodiment, the image forming apparatus
consists of the printing station PS and the operator's station OS
and the printing station PS includes the printing unit PU, the
loop-forming unit RU, the heating fixing unit HU and the slow
cooling unit CU. It should be noted, however, that the minimal
constituents of the image forming apparatus of the invention are
the heating fixing unit HU and the slow cooling unit CU. Needless
to say, the image forming apparatus may include also all the other
units or portions thereof.
[0105] Next, a further embodiment of the image forming apparatus of
the invention will be described.
[0106] An image forming apparatus shown in FIG. 12 includes a
smoothing-out mechanism D2 which is slightly different from the
corresponding mechanism employed in the foregoing embodiment. The
smoothing-out mechanism D2 of this embodiment too includes a curved
transporting section 159 for forcibly bending the cross-section
shape in its lateral view of the recording medium 1 discharged from
a heating fixing unit HU2 and bending it downward also.
[0107] The curved transporting section 159 of this embodiment,
however, consists of an angular member 160 extending straight along
the width direction of the recording medium 1 and a guide mechanism
170 for forcibly bending the recording medium 1 by pressing this
medium 1 against the angular member 160. Further, the smoothing-out
mechanism D2 of this embodiment does not include the press roller
mechanism constituted from the vertically movable rollers; and the
transport roller mechanism 158 disposed adjacent the exit of the
heating fixing unit HU2 includes three rollers rotatably supported
about stationary horizontal shafts, like the upstream transport
roller mechanism 54b.
[0108] The angular member 160 includes a first flat plate member
160a extending parallel with the recording medium 1 discharged from
the heating fixing unit HU2 and a second flat plate member 160b
extending downward from the rear end of this first flat plate
member 160a at an angle of 90 degrees. And, the connecting portion
between the first flat plate member 160a and the second flat plate
member 160b forms a projecting corner 160c having a right-angled
cross section. The angular member 160 mounts, on its inner face, an
electric heater 161 for heating the angular member 160 and a
temperature sensor 162 for detecting the temperature of the angular
member 160. In operation, the power to be supplied to the electric
heater 161 is controlled so that the temperature detected by this
temperature sensor 162 may be maintained at 180.degree. C.
[0109] The guide mechanism 170 includes a first guide member 171
inclined downward relative to the posture of the leading end of the
recording medium discharged and a second guide member 172 extending
perpendicularly downward from the lower end of the first guide
member 171. The discharged recording medium 1 will be guided with
displacement by the first guide member 171 and the second guide
member 172. As the amount of the medium discharged is increased,
the medium will be discharged while being pressed against the
heated corner 160c of the angular member 160 as being assisted by
the effect of the dead weight of the recording medium 1 per se. As
a result, the recording medium 1 will be bent as viewed from the
lateral side thereof. Thus, the type of wrinkles appearing as
wave-like undulations in the cross section of the recording medium
1 may be effectively eliminated or occurrence of such wrinkles may
be avoided in advance. At the same time, as the recording medium 1
is pressed along its entire width against the heated corner 160c of
the angular member 160, the medium 1 will be discharged while being
subjected to the strong flattening effect from the corner 160c.
[0110] The curved transporting section 159 includes a pair of side
wall members 173. These side wall members 173 cooperate with the
first guide member 171 and the second guide member 172 to form a
downwardly opened space S. This space S serves to realize mild heat
discharge from the recording medium 1 by avoiding rapid cooling
thereof.
[0111] Downwardly of this space S, there are provided a third guide
member 174 which supports the recording medium 1 from the back face
thereof and a stocker 180 made of cloth and disposed with an
inclined posture with its leading end located downwards. The third
guide member 174 and the stocker 180 guide the recording medium 1
not toward the position immediately below the space S, but in a
direction away from the heating fixing unit HU2. This stocker 180
has a width greater than the maximum width of the recording medium
1 which can be processed. And, its inside has a lining of sheet
made of polyester fibers having good heat resistance and interwoven
with carbon fibers having conductivity for eliminating static
electrical charge. The upper end of the stocker 180 is supported to
a horizontal first rod 181 and its lower end is supported to a
second rod 182 mounted on the floor. And, the opposed ends of this
lower second rod 182 are supported to a stay 183 extending from the
support leg 53 of the heating fixing unit HU2. With these, the
stocker 180 is maintained with an inclined posture in which the
stocker extends downwardly away from the heating fixing unit
HU2.
[0112] As shown in FIG. 2, at a position upwardly of the
smoothing-out section D2, there is provided a unit adapted for
collecting odorous substance such as mist or gas generated at the
heating fixing unit HU2. This unit includes a duct 190 which is
open at the bottom thereof, an electric-powered fan 191 for sucking
the mist or gas collected by this duct 190 and an eliminating
mechanism 192 for eliminating the mist or the gas. This eliminating
mechanism 192 may be adapted for eliminating the odor by adsorbing
the mist or gas or by a chemical reaction therewith or by activity
of microorganism. Specifically, the mechanism can comprise
activated carbon, silica gel, zeolite, calcium silicate, ozone
deodorizer, photocatalytic device, scrubbing deodorizer, etc.
[0113] The transport rollers excluding the introduction rollers
54a, the transmission mechanism for providing rotational drive to
these transport rollers, the third guide member 174 and the
smoothing-out section D2 are all supported via a slide frame 20 to
the main case 50. The slide frame 20 is sidable toward the
downstream side in the transporting direction of the recording
medium 1. The slide frame 20 includes a pair of transmission cases
21 disposed at opposed ends of the transport rollers, a bottom wall
22 disposed at position interconnecting these transmission cases
21, and a frame interconnecting these components. And, this slide
frame 20 is supported to be switchable by a sliding operation
thereof between a condition where the frame is drawn out on the
side of the rear face of the main case 50 and a further position
where the frame is set and stored within the main case 50. In order
to realize this sliding operation, between the slide frame 20 and
the main case 50, there is interposed a linear guide mechanism
including a pair of guide rails 23 supported in parallel with each
other and steel balls (not shown) supporting the guide rails 23
such the rails 23 are sidable relative to each other.
[0114] A transport motor M1 is provided downwardly of the frame 50F
of the main case 50. An intermediate gear 25 meshing with an output
gear 24 of this transport motor M1 is supported to the main case
and an input gear 26 meshing with this intermediate gear 25 is
supported to one side face of the transmission case 21. The
transmission case 21 accommodates therein an input sprocket 27
rotatable in unison with the input gear 26, an endless chain 29 for
transmitting the rotational drive of the input sprocket 27 to the
respective transport rollers (such as the transport roller 158d),
and a tension roller 28 for providing a tension to the endless
chain 29.
[0115] The construction of the slide frame 20 and the construction
of the transporting mechanism including the transport motor Ml can
be applied also to the first embodiment described hereinbefore.
[0116] The invention may be embodied in any other manner as
described above. Further changes or modifications will be apparent
for those skilled in the art from the foregoing disclosure within
the scope of the invention defined in the appended claims.
* * * * *